Temperature-dependent capacitance–voltage and current–voltage characteristics of Pt/Ga2O3 (001) Schottky barrier diodes fabricated on n––Ga2O3 drift layers grown by halide vapor phase epitaxy

Abstract

We investigated the temperature-dependent electrical properties of Pt/Ga2O3 Schottky barrier diodes (SBDs) fabricated on n–-Ga2O3 drift layers grown on single-crystal n+-Ga2O3 (001) substrates by halide vapor phase epitaxy. In an operating temperature range from 21 °C to 200 °C, the Pt/Ga2O3 (001) Schottky contact exhibited a zero-bias barrier height of 1.09–1.15 eV with a constant near-unity ideality factor. The current–voltage characteristics of the SBDs were well-modeled by thermionic emission in the forward regime and thermionic field emission in the reverse regime over the entire temperature range.

Schottky barrier diode based on β-Ga2O3 (100) single crystal substrate and its temperature-dependent electrical characteristics

“…. This current density is comparable to the reported highest values in the Pt/Ga 2 O 3 Schottky diodes, 21,23 and much larger than those in Cu/ Ga 2 O 3 , 22 and Au/Ga 2 O 3 diodes. 24 From the fitting line of the linear region in Figure 2(b), we can abstract that the threshold voltage or built-in potential (V bi ) is about 1.07 V. From the slope of the fitting line, the ON-resistance (R ON ) is about 159 X or 12.5 mX cm 2 , which is relatively high because of the low conductivity and carrier density of the substrate, but comparable to the reported values in the Pt/Ga 2 O 3 Schottky diodes.…”

“…24 From the fitting line of the linear region in Figure 2(b), we can abstract that the threshold voltage or built-in potential (V bi ) is about 1.07 V. From the slope of the fitting line, the ON-resistance (R ON ) is about 159 X or 12.5 mX cm 2 , which is relatively high because of the low conductivity and carrier density of the substrate, but comparable to the reported values in the Pt/Ga 2 O 3 Schottky diodes. 21,23 In the inset of Figure 2(b), by linearly extrapolating J to zero voltage, the saturation current density (J 0 ) is determined to be 2 Â 10 À16 A/cm 2 , and from the subthreshold slope the ideality factor (n) can be got as about 1.1, which is close to unity. This value is also low enough compared to those of the previously reported Pt/Ga 2 O 3 , 21,23 Cu/ Ga 2 O 3 , 22 and Au/Ga 2 O 3 Schottky diodes.…”

“…21,23 In the inset of Figure 2(b), by linearly extrapolating J to zero voltage, the saturation current density (J 0 ) is determined to be 2 Â 10 À16 A/cm 2 , and from the subthreshold slope the ideality factor (n) can be got as about 1.1, which is close to unity. This value is also low enough compared to those of the previously reported Pt/Ga 2 O 3 , 21,23 Cu/ Ga 2 O 3 , 22 and Au/Ga 2 O 3 Schottky diodes. 24 According to the thermionic emission theory, we can abstract the other performance parameters of the diode.…”

“…In Figure 1(b), the red curve is the X-ray diffraction (XRD) result of Ga 2 O 3 substrate. As is shown that, the surface 21,27,28 From the result of the secondary ion mass spectroscopy (SIMS) spectrum of our b-Ga 2 O 3 substrate (data not shown), it is found that a certain amount of Sn impurities exist in the Ga 2 O 3 substrate. Due to the unintentional Sn impurity incorporation during the EFG growth, our Ga 2 O 3 substrate shows the n-type conduction.…”

“…The easy, low-cost, and mass-producible melt-growth methods at atmospheric pressure, such as floating zone (FZ) 17,18 and the edge-defined film-fed growth (EFG), [19][20][21] have been utilized to fabricate the single-crystal b-Ga 2 O 3 substrates. Schottky diode based on the b-Ga 2 O 3 (001), 21 ( 201), 20,22 and (010) 23 substrate has been studied, but (100)-oriented bulk single crystal is rarely used in SBD, 24 especially by the EFG method. At the same time, the b-Ga 2 O 3 (100) substrate can be obtained by mechanical exfoliation method and has the advantage of easy fabrication, low surface layer damage, and ultra-smooth crystal surface.…”